*> 100 Cool Things - http://cobolrocks.codeplex.com/
*> Copyright (c) 2009-2010
*> by Emerson Lopes (emersonlopes@gmail.com)
*>
*> Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated 
*> documentation files (the "Software"), to deal in the Software without restriction, including without limitation 
*> the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and 
*> to permit persons to whom the Software is furnished to do so, subject to the following conditions:
*>
*> The above copyright notice and this permission notice shall be included in all copies or substantial portions 
*> of the Software.
*>
*> THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED 
*> TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
*> THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF 
*> CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
*> DEALINGS IN THE SOFTWARE.

CLASS-ID. NonTerminalExpression AS "InterpreterPattern.NonTerminalExpression".

    environment division.
        configuration section.
            repository.
                class ClassContext              as "InterpreterPattern.Context"
                class SystemCollectionHashTable as "System.Collections.Hashtable"
                class SystemString              as "System.String"
                
                interface IExpression           as "InterpreterPattern.IExpression".
                
 *> Instance's data and methods
    object. implements IExpression.
        data division.
            working-storage section.
            copy "types.book".
   
            01  leftNode      object reference IExpression private.          
            01  rightNode     object reference IExpression private.          
            
        procedure division.
        
            method-id. NEW.
                 data division.
                     linkage section.
                     01   inLeftExpression  object reference IExpression.
                     01   inRightExpression object reference IExpression.

                 procedure division using inLeftExpression inRightExpression.
                     
                     invoke self "SetLeftNode"    using inLeftExpression
                     invoke self "SetRightNode"   using inRightExpression
                 
            end method NEW.
            
             method-id. SetLeftNode.
                data division.
                    linkage section.
                    
                    01 inNode     object reference IExpression.
                
                procedure division using inNode.
                
                    set  leftNode         to  inNode
                       
            end method SetLeftNode.   

             method-id. SetRightNode.
                data division.
                    linkage section.
                    
                    01 inNode     object reference IExpression.
                
                procedure division using inNode.
                
                    set  rightNode         to  inNode
                      
            end method SetRightNode.   

             method-id. GetLeftNode.
                data division.
                    linkage section.
                    
                    01 outNode     object reference IExpression.
                
                procedure division returning outNode.
                
                    set  outNode          to  leftNode
                       
            end method GetLeftNode.   

             method-id. GetRightNode.
                data division.
                    linkage section.
                    
                    01 outNode     object reference IExpression.
                
                procedure division returning outNode.
                
                    set  outNode           to  rightNode
                       
            end method GetRightNode.   

            method-id. EvaluateExpression as "Evaluate".
                data division.
                    linkage section.
                    
                    01 inContext  object reference ClassContext.
                    01 outValue   type SystemDouble.
                
                procedure division using inContext returning outValue.
                
                    *> Implemented because NetCobol.Net does not supports Abstract classes
                       
            end method EvaluateExpression.
    end object.
END CLASS NonTerminalExpression.
